The present invention relates generally to resins for use in chromatography, and more particularly to an improved surface graft modified resin that is specifically adapted to provide enhanced chromatographic performance throughout chromatographic applications.
The use of chromatography in pharmaceutical, biotechnology and environmental research industries is well known. Chromatography is a vital process in these industries as it is applied upon many aspects of their business. For example, chromatography can be used to prepare and analyze drug samples, purify various essential chemicals, and has large-scale applications such as cleansing aqueous solutions of any toxic materials.
Traditionally, the most widely utilized resins have been silica-based. Because silica resins have been so widely employed, methods and chemicals for their modification are well documented in the art and commercially available. In recent years, however, polymer-based resins have gained popularity due to advantageous chromatographic properties over silica-based resins such as high surface area and pH stability.
Most polymer-based resins are formed through co-polymerization of two or more monomers. A monomer is a substance of which each of its molecules can contribute one or more constitutional units in the structure of a macromolecule. In this context, co-polymerization is a chemical reaction that links two or more different monomers together to form a co-polymer.
In these resins, monomers of various desired properties are co-polymerized in the presence of an initiator and a porogenic solvent to start a chain reaction. Depending on a number of factors (e.g., ratio of the monomers used, initiator, porogenic solvent, temperature and the like), the resulting resins will have varying physical structures or morphology, as well as varying chemical properties. Exemplary types of these resins are (poly)styrene-divinylbenzene and (poly)methacrylates. Unfortunately, most of the “off-the-shelf” variants of these resins have a limited range of chemical properties, thus limiting the number of chromatographic applications for which they may be applied.
One approach to alleviating this deficiency is to alter the monomers used during co-polymerization to produce resins with unique chromatographic characteristics. However, such approach is disadvantageous as by altering the co-polymerization conditions (e.g., monomers, temperature, initiators, etc.), the physical structure of the resulting resin may be undesirably changed in a way that is no longer ideal for the intended chromatographic application. As such, forming resins with proper physical and chemical qualities in the above-noted manner can require extensive and grueling research.
Some resins are also produced by using Merryfield Resins and Friedal Crafts reactions. These techniques chemically modify the existing resins at their surfaces. However, Merryfield resins are often undesirable as they require a two-step reaction in order to achieve the suitable derivitized surface, and is thus time-consuming. Moreover, Freidal Crafts reactions require the use of metal catalysts which in many chromatographic techniques can cause unwanted adsorption of metal-chelating compounds. In addition, Freidal Crafts reactions further require strict control over reaction conditions, making consistent reproductions of resins a challenge.
In view of the above-described shortcomings of prior art resins, there exists a need in the art for an improved chemically-modified resin which achieves desired chromatographic properties through a one-step reaction without altering the ideal physical/chemical characteristics thereof. Moreover, there exists a need for an improved chemically-modified resin that can be readily manufactured in a time-efficient manner, while being reproducible on a consistent basis.